Currently working a deal on a 69 fastback w/ a 351 Cleveland & would like to know if anyone knows what the backspacing is. As you can see from the pic the rims gotta go lol. Looking to join the typical crowd that uses Magnum 500's shown in the other picture. Way I see it, why not stick with something that works? Anyway, the size I'm looking at is 15x10 which have a 5" or 5.5" backspacing & hope to throw on a pair of 335 Nitto 555R's. Any ideas on the backspacing & if the width would be too great?

 

335 won't fit unless you mini-tub it and even then it might not as I think it'll be way too close to the leaf spring...
check out this link.
It's done! - Page 3 - 1969 Mustang Supersite Web Forums

 

^^^ Theres some nice rides in there!

 

hmmm ... I'm not planning on going as wide as him in the front being I'm prolly gonna stick to a 15x7 in the front but I definitely see your point for the rears. "Supposedly" a 285 wouldn't be an issue but I'm definitely thinkin' I'm gonna have to ask him what all he did to the inner fender. That or just stick to runnin' 275's on a pair of 15x8's.

Side note ... those Fikse FM5's are about $1,200 (each) for the rear. Kinda makes me hate him lol.